Purpose: Despite literature showing a correlation between oral language and written language ability, there is little evidence documenting a causal connection between oral and written language skills. The current study examines the extent to which oral language instruction using narratives impacts students’ writing skills. Method: Following multiple baseline design conventions to minimize threats to internal validity, 3 groups of 1st-grade students were exposed to staggered baseline, intervention, and maintenance conditions. During the intervention condition, groups received 6 sessions of small-group oral narrative instruction over 2 weeks. Separated in the school day from the instruction, students wrote their own stories, forming the dependent variable across baseline, intervention, and maintenance conditions. Written stories were analyzed for story structure and language complexity using a narrative scoring flow chart based on current academic standards. Results: Corresponding to the onset of oral narrative instruction, all but 1 student showed meaningful improvements in story writing. All 4 students, for whom improvements were observed and maintenance data were available, continued to produce written narratives above baseline levels once the instruction was withdrawn. Conclusions: Results suggest that narrative instruction delivered exclusively in an oral modality had a positive effect on students’ writing. Implications include the efficiency and inclusiveness of oral language instruction to improve writing quality, especially for young students.